imp(ibc-testkit): Tendermint proof verifications via integration test

[rnbguy]

Closes: #398

Description

Adds integration tests for combinations of MockHost and TendermintHost.

• Client creation
• Connection creation
• Channel creation
• Packet relay

Since it includes TendermintHost, these tests also exercise commitment proof validations in Tendermint light clients.

The PR also includes a unit test for minimal proof validations.

Additionally, to maintain the ics23 proof spec, a main_store is introduced in MockGenericContext - that stores the IBC store root at IBC commitment prefix path. The blocks are now generated with the root of the main_store.

To keep the proof retrieval minimal, I had to modify the ProvableContext::get_proof of MockIbcStore. Before it returned the encoded bytes of a singleCommitmentProof. Now it returns the encoded bytes of MerkleProofs, which is essentially a list of CommitmentProofs corresponding to a MerklePath.

Two shortcomings of basecoin_store:

• No support for cosmos-sdk specs informalsystems/basecoin-rs#171
• No support for non-membership proofs informalsystems/basecoin-rs#158

---

PR author checklist:

• [ ] Added changelog entry, using unclog.
• [x] Added tests.
• [x] Linked to GitHub issue.
• [x] Updated code comments and documentation (e.g., docs/).
• [x] Tagged one reviewer who will be the one responsible for shepherding this PR.

Reviewer checklist:

• [ ] Reviewed Files changed in the GitHub PR explorer.
• [ ] Manually tested (in case integration/unit/mock tests are absent).

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 88.26896% with 164 lines in your changes are missing coverage. Please review.

Project coverage is 66.33%. Comparing base (05ea5fa) to head (410b8ad).

Files	Patch %	Lines
ibc-testkit/src/relayer/utils.rs	89.22%	90 Missing :warning:
ibc-testkit/src/relayer/context.rs	74.38%	73 Missing :warning:
ibc-testkit/src/relayer/integration.rs	99.16%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## feat/refactor-testkit #1146 +/- ## ========================================================= + Coverage 64.36% 66.33% +1.96% ========================================================= Files 221 223 +2 Lines 21216 22397 +1181 ========================================================= + Hits 13656 14856 +1200 + Misses 7560 7541 -19 ```

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